Really sounds like 燒爭口or 盤裂。Both case will cause
leakage so that pressure inside the engine will
drop, which will cause (i) 無力 (ii) 低轉振。If 出白
煙,then more sure (because water gets in engine and
gets vaporized)。
據我所知,冷卻系統應該無流經波箱,therefore nothing to
do with 波箱。
If 燒爭口, shouldn't be very expensive, but if 盤裂就大鑊d。